The bias bias

From the Washington Post:

Partisans, it turns out, don't just arrive at different conclusions; they see entirely different worlds . In one especially telling experiment, researchers showed 144 observers six television news segments about Israel's 1982 war with Lebanon.

Pro-Arab viewers heard 42 references that painted Israel in a positive light and 26 references that painted Israel unfavorably.

Pro-Israeli viewers, who watched the very same clips, spotted 16 references that painted Israel positively and 57 references that painted Israel negatively.

Both groups were certain they were right and that the other side didn't know what it was talking about.

The tendency to see bias in the news -- now the raison d'etre of much of the blogosphere -- is such a reliable indicator of partisan thinking that researchers coined a term, "hostile media effect," to describe the sincere belief among partisans that news reports are painting them in the worst possible light.

Were pro-Israeli and pro-Arab viewers who were especially knowledgeable about the conflict immune from such distortions? Amazingly, it turned out to be exactly the opposite, Stanford psychologist Lee D. Ross said. The best-informed partisans were the most likely to see bias against their side.

Ross thinks this is because partisans often feel the news lacks context. Instead of just showing a missile killing civilians, in other words, partisans on both sides want the news to explain the history of events that prompted -- and could have justified -- the missile. The more knowledgeable people are, the more context they find missing.

Even more curious, the hostile media effect seems to apply only to news sources that strive for balance. News reports from obviously biased sources usually draw fewer charges of bias. Partisans, it turns out, find it easier to countenance obvious propaganda than news accounts that explore both sides.